Polyurethane elastic fibers obtained from 4,4'-diphenylmethane diisocyanate, polyhydroxy polymer with a relatively low degree of polymerization, multifunctional active hydrogen compounds, and so on exhibit high rubber elasticity, superior mechanical properties in tensile stress and recoverability, and excellent thermal property. For this reason, they have been given much attention and used as functional materials for clothes such as foundation garments, socks, sportswears, and so on.
However, it has been known that exposure of goods made with elastic fibers which have been formed mainly from long chain synthetic elastic segmented polyurethanes to chlorinated aqueous environments with chlorine bleaching agents can cause considerable lowering of the physical properties of the segmented polyurethane. It has been also known that swimwear made with polyurethane fibers and polyamide fibers is subject to lowered physical properties of the fibers upon long-term exposure to the water in swimming pools containing 0.5-3 ppm (parts per million) active chlorine.
In fact, many attempts have been made so far to impart proof or resistance to chlorine-induced degradation. For example, U.S. Pat. No. 4340527 teaches zinc oxide, and Japanese Patent Publication No. 35283/1986 teaches magnesium oxide and aluminum oxide as additives which prevent chlorine-induced degradation.
Nevertheless, improvements are still needed since the above-mentioned polyurethane elastic fiber containing a chlorine-induced degradation inhibitor, which is used to manufacture union knit fabric loses most of the resistance to chlorine after dyeing, etc., because the degradation inhibitor once contained in the fiber elutes out during dyeing, finishing and processing stages, particularly during the dyeing process which the goods made of the union knit fabric undergo, due to a low pH of dye liquor despite the resistance to chlorine which the raw fiber possesses.
The present invention provides resistance to the chlorinated water to the dyed textile goods made with at least a polyurethane elastic fiber, and a method for manufacturing them, thereby resolving the problems of the prior art as described above.
That is, the present invention relates to a dyed union knit fabric comprised of at least a polyurethane elastic fiber, and a polyamide fiber and/or a cation dyeable polyester fiber, wherein the polyurethane elastic fiber contains one or more from among magnesium oxide, zinc oxide, aluminium oxide, magnesium hydroxide, zinc hydroxide, aluminum hydroxide and hydrotalcite compounds of Mg.sub.x Al.sub.y (OH).sub.z CO.sub.3. IH.sub.2 O in a proportion of 0.5-4.5 weight %. Also, the present invention relates to a method for manufacturing a dyed union knit fabric wherein pH of dye liquor is maintained at not less than 4.5 from the beginning to the end of dyeing process for the union knit fabric comprised of at least a polyurethane elastic fiber containing one or more of the above-mentioned compounds in a proportion of 0.5-5.0 weight, and a polyamide fiber and/or a cation dyeable polyester fiber, with the use of acid dyes, metal-complex dyes, fluorescent dyes, disperse dyes, or the like.
The polyurethane elastic fiber used in the present invention is an elastic fiber obtained by spinning a polymer composition containing a polyurethane to be mentioned below as a main component.
As the polyurethane in the present invention, usable are polymers obtained by reacting a polymer diol having a number average molecular weight of not less than 600, preferably 1000-5000 and a melting point of not more than 60.degree. C., an isocyanate based on an organic diisocyanate, and a multifunctional active hydrogen compound having a molecular weight of not more than 400.
Examples of the polymer diol include polyether glycols such as polytetramethylene ether glycol and polyethylene propylene ether glycol; polyester glycols obtained by reacting at least one member of glycols such as ethylene glycol, 1,6-hexane diol, 1,4-butane diol and neopentyl glycol with at least one member of dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid, .beta.-methyladipic acid and isophthalic acid; polycaprolactone glycol; polyhexamethylene dicarbonate glycol; and mixtures and copolymers of two or more of them.
Examples of the organic diisocyanate include 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, hexamethylene diisocyanate, 1,4-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, and mixtures of two or more of them. A small amount of triisocyanate may be co-used.
Examples of the multifunctional active hydrogen compounds include ethylenediamine, 1,2-propylenediamine, hexamethylenediamine, xylylenediamine, 4,4'-diphenylmethanediamine, hydrazine, 1,4-diaminopiperazine, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, water, and mixtures of two or more of them. A small amount of a terminator such as monoamine or monoalcohol may be added to the above-mentioned compounds, if desired. Of those, preferred is diamine solely or one based on diamine.
The way of forming an elastic fiber by spinning a composition based on polyurethane is not subject to particular limitation, but dry spinning of a composition based on polyurethane, which is dissolved in a solvent is preferable. As the solvent, there may be exemplified, but not limited to, N,N-dimethylformamide, N,N-dimethylacetamide, tetramethylurea and hexamethylphosphoramide. The components other than polyurethane to be contained in the composition based on polyurethane include chlorine-induced degradation inhibitors such as metal oxides and metal hydroxides (e.g. magnesium oxide, zinc oxide, aluminum oxide, magnesium hydroxide, zinc hydroxide, aluminum hydroxide, hydrotalcite compounds) which may be used solely or in combination, with preference given to magnesium oxide and zinc oxide. The way of adding an inhibitor into the polyurethane solution is not particularly limited, but preferably performed by adding same in finely divided particles having an average diameter of 0.05-3 .mu.m. The chlorine-induced degradation inhibitor such as metal oxide, etc. is added in a proportion of 0.5-5.0 weight %, preferably 1.0-3.0 weight % based on the polyurethane. The proportion of the residual magnesium oxide, etc. relative to the polyurethane after dyeing is 0.5-4.5 weight %, preferably 1.0-4.5 weight %, more preferably 2.0-4.0 weight %.
The polyurethane elastic fiber in accordance with the present invention is of 20-100 denier, preferably 40-80 denier. The elastic fiber is used in the state of covering yarn or bare yarn.
The polyamide fiber to be knitted with the polyurethane elastic fiber of the present invention is not particularly limited and exemplified by nylon 6 and nylon 6,6.
Similarly, the cation dyeable polyester fiber is not particularly limited and can be a fiber obtained from polyesters prepared by copolymerization of an ester-forming compound having a sulfo group such as 5-sulfoisophthalic acid with a conventional polyester, or copolymerization along with another ester-forming compound, wherein the sulfo group preferably forms a metal salt such as sodium salt. This cation dyeable polyester fiber can dye in sufficiently deep shade with cation dyes at a temperature of not more than 100.degree. C.
The union knit fabric is subject to no particular limitation and may be a weft-knitted fabric, a warp-knitted fabric, a tricot fabric or a raschel fabric. Its stitch may be half stitch, back half stitch, double atlas stitch, double dembhigh stitch, or the like with no particular limitation. From the standpoint of handling touch, the surface of the fabric is preferably made with a polyamide fiber and/or a cation dyeable polyester fiber.
The knit fabric is subjected to scouring, relaxing and drying under the usual conditions, in which heat setting temperature is between 150.degree. C. and 190.degree. C., preferably between 160.degree. C. and 180.degree. C.
Dyeing is done in a dye bath for 20-120 minutes, preferably for 40-60 minutes.
The dyeing machine is one usually employed, such as wince dyeing machine and liquor flow dyeing machine. The dyestuff to be used is one normally employed by dye makers for dyeing polyamide fibers or for dyeing cation dyeable polyester fibers, such as acid dyes, metal-complex dyes, fluorescent dyes, disperse dyes, cation dyes, and so on.
The polyamide fiber and/or the cation dyeable polyester fiber of the present invention exhaust(s) and/or show(s) a dye uptake of not less than 0.01% owf, preferably 0.05% owf, more preferably 0.1% of relative to the union knit fabric of at least one of the above dyes.
In the present invention, it is essential that pH of dye liquor be maintained at 4.5 or above, preferably at 5 from the initiation to the termination of dyeing, and for this to be achieved, for example, an organic acid ester is added to the dye liquor.
In the organic acid ester are formate, acetate, butyrate, lactate and orthoformate. An alkali agent such as soda ash may be used along with the organic acid ester. The organic acid ester is used in a proportion of 0.1-10 weight %, preferably 1-5 weight % based on the weight of the fabric. The preferable organic acid ester is orthoformate.
The orthoformate is exemplified by trimethyl orthoformate and triethyl orthoformate, with preference given to trimethyl orthoformate. The orthoformate is used in a proportion of 0.01-10 weight %, preferably 0.5-5 weight % based on the weight of the fabric. Where it is used in a proportion of less than 0.01 weight %, sufficient dyeing is unattainable, while used in more than 10 weight %, the chlorine-induced degradation inhibitor elutes out in a large amount, resulting in marked lowering of product properties. An alkali agent such as soda ash may be used along with the orthoformate.
An ester of formic acid and an alkylene glycol having an alkylene of 2 to 5 carbon atoms may be used for maintaining the pH of die liquor not less than 4.5. In such ester are monoesters and diesters of formic acid and ethylene glycol, and mixtures thereof; and monoesters and diesters of formic acid and propylene glycol, and mixtures thereof, with preference given to monoesters and diesters of formic acid and ethylene glycol, and mixtures thereof. The ester of formic acid and an alkylene glycol having an alkylene of 2 to 5 carbon atoms may be used in a proportion of 0.01-3.0 weight %, preferably 0.1-1.0 weight % based on the weight of the fabric. Where it is used in a proportion of less than 0.01 weight %, sufficient dyeing is unattainable, while used in more than 3.0 weight %, the chlorine-induced degradation inhibitor elutes out in a large amount, resulting in marked lowering of product properties. An alkali agent such as soda ash may be used along with the ester of formic acid and an alkylene glycol having an alkylene of 2 to 5 carbon atoms.
The present invention aims at imparting resistance to chlorine-induced degradation to a polyurethane elastic fiber while imparting resistance to change in shade to a dyed union knit fabric made with said elastic fiber.
It has been known that products dyed with mixed dyes of acid dyes, dispersion dyes, metal-complex dyes, reactive dyes and direct dyes are susceptible to shade change in chlorinated environments. In particular, a long-term exposure of a union knit fabric made with a polyurethane elastic fiber and a polyamide synthetic fiber, and dyed with acid dyes, dispersion dyes, metal-complex dyes or reactive dyes to the chlorinated water containing 0.5-3 ppm active chlorine such as the water in swimming pools results in decoloring, yellowing and saddening of the shade of the fabric particularly when the fabric has been dyed in fluorescent or brilliant shades.
In view of the above situation, the present inventors have conducted intensive studies based on a new idea and as a result, achieved the present invention which remarkably resolves various problems as described.
That is, the present invention provides a union knit fabric comprised of at least a polyurethane elastic fiber, and a polyamide fiber and/or a polyester fiber, which has been dyed with mixed dyes of acid dyes, dispersion dyes, metal-complex dyes, reactive dyes and direct dyes, and markedly improved in resistance to chlorine-induced change in shade in various chlorinated environments without impairing the original color of the fabric by allowing to contain at least one compound having a reaction amount of chlorine of 50 milliequivalent per gram or more, specifically one member of mono- and/or polyhydroxybenzene derivatives of the following formula 1, 2 or 3 in a proportion of 0.1-20% relative to the weight of the fiber via immersion in a hot bath, and a method for manufacturing it. In addition to the resistance to chlorine-induced degradation, resistance to chlorine-induced change in shade can be increased by blending said compounds during dyeing and/or before and after the dyeing. ##STR1## wherein Z.sup.1 is an aromatic group; Z.sup.2, Z.sup.3, Z.sup.4 and Z.sup.5 are independently aromatic groups the same as or different from Z.sup.1 ; A is a bivalent group such as alkylene, sulfonyl, sulfide and azo; B.sup.1 is a monovalent group such as alkyl, alkoxy, nitro, sulfone and amino, or hydrogen atom; B.sup.2, B.sup.3, B.sup.4 and B.sup.5 are independently monovalent groups the same as or different from B.sup.1, or hydrogen atom; R.sup.1 and R.sup.2 are the same or different and each is a group selected from the group consisting of alkyl and aryl; and k, l, m, n, s, t, u, v, x add y are positive integers satisfying the following formulas Q-1 to Q-5.
______________________________________ 0 .ltoreq. k .ltoreq. 4 1 .ltoreq. k + 1 .ltoreq. 5 (Q-1) 0 .ltoreq. m .ltoreq. 4 1 .ltoreq. m + n .ltoreq. 5 (Q-2) 0 .ltoreq. s .ltoreq. 4 1 .ltoreq. s + t .ltoreq. 5 (Q-3) 0 .ltoreq. u .ltoreq. 4 1 .ltoreq. u + v .ltoreq. 5 (Q-4) 1 .ltoreq. x .ltoreq. 4 1 .ltoreq. x + y .ltoreq. 6 (Q-5) ______________________________________
Each symbol in formulas (I) to (III) represents the following. As regards Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4 and Z.sup.5, the aromatic group means phenylene group such as 1,4-phenylene, 1,3-phenylene and 1,2-phenylene, naphthylene group such as 1,4-naphthylene, 1,5-naphthylene and 1,6-naphthylene.
As regards A, the alkylene group has 1 to 20, preferably 1 to 10 carbon atoms, which is exemplified by methylene, ethylene, propylene, trimethylene, vinylene, ethynylene and propenylene.
As regards B, the alkyl group has 1 to 10, preferably 1 to 5 carbon atoms, which is exemplified by methyl, ethyl, propyl, isopropyl, butyl and t-butyl.
As regards B, the alkoxy group has 1 to 10, preferably 1 to 5 carbon atoms, which is exemplified by methoxy, ethoxy, propoxy, isopropoxy and butoxy.
As regards R.sup.1 and R.sup.2, the alkyl group has 1 to 10, preferably 1 to 5 carbon atoms, which is exemplified by methyl, ethyl, propyl, isopropyl, butyl and t-butyl.
As regards R.sup.1 and .sup.2, the aryl group is exemplified by phenyl, tolyl, xylyl, biphenyl and naphthyl.
The compounds of formula (I) may be exemplified by diphenylmethane derivatives into which a hydroxyl group has been introduced, such as 4,4'-methylenebisphenol, 4,4'-(1-methylethylidene)bisphenol, 4,4'-ethylidenebisphenol, 4,4'-(1-.alpha.-methylbenzylidene)bisphenol, 4,4'-cyclohexylidenebisphenol, 4,4'- 1- 4- 2-(4-hydroxyphenyl)-2-propyl!phenyl!ethylidene!bisphenol, 4,4'- (4-hydroxyphenyl)methylene!bis(methylphenol), 4,4'- (4-hydroxyphenyl)methylene!bis(2,6-dimethylphenol), 4,4'-methylethylidene)bis(2-methylphenol), 4,4',4"-ethylidinetrisphenol, 4,4',4"-methylidinetrisphenol, 2,2'-methylenebis(4-methylphenol), 4,4'-(1-methylethylidene)bis(2,6-dimethylphenol), phenolphthalein, 1,4-phenylene-4,4'-bisphenol, 1,4-bis(4-hydroxyphenyl)cyclohexane, bis(3,5-dihydoxyphenyl)methane, 2,2'-bis(4-hydroxynaphthyl)methane, 2,2'-bis(5-hydroxynaphthyl)methane, 2,2'-bis(6-hydroxynaphthyl)methane, 2,2'-bis(7-hydroxynaphthyl)methane, 2,2'-bis(8-hydroxynaphthyl)methane, 2,2'-bis-(4,7-dihydroxynaphthyl)methane, 2,2'-bis(3,6-dihydroxynaphthyl)methane, and polymers obtained by using them as monomers; diphenylsulfone derivatives into which a hydroxyl group has been introduced, such as bis(4-hydroxyphenyl)sulfone and bis(3,5-dihydroxyphenyl)sulfone, and polymers obtained by using them as monomers; diphenylsulfid derivatives into which a hydroxyl group has been introduced, such as 4,4'-dihydroxydiphenylsulfid and bis(3,5-dihydroxyphenyl)sulfid, and polymers obtained by using them as monomers; diphenylether derivatives into which a hydroxyl group has been introduced, such as 4,4'-dihydroxydiphenyl ether and bis(3,5-dihydroxyphenyl) ether, and polymers obtained by using them as monomers; and azobenzene derivatives into which a hydroxyl group has been introduced, such as 4,4'-dihydroxyazobenzene and bis(3,5-dihydroxy)azobenzene, and polymers obtained by using them as monomers.
Examples of the compounds of formula (II) include biphenyl derivatives into which a hydroxyl group has been introduced, such as 2-phenylphenol, 3-phenylphenol, 4-phenylphenol, 3,3'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl, 3,5-dihydroxybiphenyl, 2,4-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, 2,3'-dihydroxybiphenyl, 3,5,4'-trihydroxybiphenyl, 2,4,4'-trihydroxybiphenyl, 2,6,4'-trihydroxybiphenyl, 3,3', 5,5'-tetrahydroxybiphenyl, and polymers obtained by using them as monomers; and binaphthyl derivatives into which a hydroxyl group has been introduced, such as 2,2'-bis(4-hydroxynaphthyl), 2,2'-bis(5-hydroxynaphthyl), 2,2'-bis(6-hydroxynaphthyl), 3,3'-bis(6-hydroxynaphthyl), 2,2'-bis(8-hydroxynaphthyl), 1,1'-bis(3-hydroxynaphthyl), 1,1'-bis(4-hydroxynaphthyl), 1,1'-bis(5-hydroxynaphthyl), 1,1'-bis(6-hydroxynaphthyl), 1,1'-bis(7-hydroxynaphthyl), 1,1'-bis(8-hydroxynaphthyl), and polymers obtained by using them as monomers.
Examples of the compounds of formula (III) include 3-hydroxybenzoic acid and/or its methyl, ethyl, isopropyl, t-butyl, amyl and stearyl esters using the 3-hydroxybenzoic acid as an acid component, and polymers obtained by using them as monomers; 4-hydroxybenzoic acid and/or its methyl, ethyl, isopropyl, t-butyl, amyl and stearyl esters using the 4-hydroxybenzoic acid as an acid component, and polymers obtained by using them as monomers; 3,5-dihydroxybenzoic acid and/or its methyl, ethyl, isopropyl, t-butyl, amyl and stearyl esters using the 3,5-hydroxybenzoic acid as an acid component, and polymers obtained by using them as monomers, 2,4-dihydroxybenzoic acid and/or its methyl, ethyl, isopropyl, t-butyl, amyl and stearyl esters using the 2,4-hydroxybenzoic acid as an acid component, and polymers obtained by using them as monomers; hydroxyacetophenones such as 3-hydroxyacetophenone, 4-dihydroxyacetophenone, 3,5-dihydroxyacetophenone and 2,4-dihydroxyacetophenone, and polymers obtained by using them as monomers; hydroxybenzyl ketones such as 3-hydroxybenzyl ethyl ketone, 4-hydroxybenzyl ethyl ketone, 3-hydroxybenzyl isopropyl ketone, 4-hydroxybenzyl isopropyl ketone, 3-hydroxybenzyl butyl ketone, 4-hydroxybenzyl butyl ketone, 3-hydroxybenzyl amyl ketone, 4-hydroxybenzyl amyl ketone, 4-hydroxybenzyl stearyl ketone and 3-hydroxybenzyl stearyl ketone, and polymers obtained by using them as monomers; and alkylphenols such as isopropylphenol, butylphenol and amylphenol, and polymers obtained by using them as monomers.
Of the polymers obtained by using mono- and/or polyhydroxybenzene derivatives of formula 1, 2 or 3 as monomers, a polymer wherein aromatic ring is directly bound with aromatic ring, which can be produced by oxidative coupling of the monomers, is preferable. Such a polymer can be produced by a well-known method such as an oxidative coupling of phenol compounds by horse-radish peroxidase. A formalin condensate obtained from the phenol compounds described above, such as the conventional novolak resin may be used.
A method for determining the amount of chlorine reacting with the compounds to be added for the improved resistance to chlorine-induced shade change is as follows.